Dobrowolsky



(No Model.)

M. VON DOLIVO-DOBROWOLSKY.

ALTERNATING CURRENT MOTOR.

Patented July 28, 1891.

m: Norms PETERS co., wonmmm. wmawm'ox, n. c.

UNITED STATES PATENT OFFICE.

MICHAEL VON DOLlVO-DOBROVOLSKY, OF BERLIN, GERMANY, ASSIGUOR- TO THE ALLGEMEINE ELEKTRICl'lri'iS-GESELLSCHAFT, OF SAME PLACE.

ALTERNATlNG-CURRENT MOTOR.

SPECIFICATION forming part of Letters Patent No. 456,804, dated July 28, 1891.

Application filed December 28, 1890. Serial No. 376,630. (No model.)

To all whom, it may concern: connection the same decrease of tension, so

Be it known that 1, MICHAEL VON DOLIVO- that the individual. circuits would present the DOBRoWoLsKY, a subject of the Emperor of same potentials at the said point, even if Russia, residing at Berlin, Prussia, have inthey were not connected together.

Vented a new and useful Improvement in Al- In the annexed drawings, Figure 1 is adiaternating-Current Motors, whereof the followgrammatic view of a motor M, arranged acing is a specification. cording to my invention,in combination with My invention relates to such electric motors a dynamo G for producing differential phase as are driven by a plurality of alternating alternating currents. Fig. 2 is a perspective IO currents of respectively (littering phases. As view of the system of conductor-bars belong- 6c is well known,motion is produced in the said ing to the motor. Fig.3 is a longitudinal secmotors in this manner, that the alternating tional view of the motor. currents are caused to generate in a body of The motor M, Figs. 1 and 3, consists in the iron, constituting a field-magnet, magnetic body of iron 1, constituting the field-magnet,

[5 poles which continuously alter their position, and composed of a series of annular disks, and that an armature placed movably under six conductor-bars b b c c dd, Figs. 1 and 9, the influence of the said poles is forced by the the conductive ring 6, to which the bars are latter to partake of their motion. fixed,and the armature f, provided with a plu- The improvement forming the subject of rality of coils. The armature is mounted on 20 my invention consists in the particular arthe shaft g rotating in the bearings h. The rangement and combination, with the motor, thick lines '11, Fig.- 3, denote the insulatingof the conductors serving to receive the operfilms serving to prevent electric contact beating currents; and its purpose is to simplify tween the conductorbars and the ring c on the motor, to impart to it greater stability, one hand and the body a and other parts on 25 to enhance the securityot' its keeping in workthe other hand. big order, and to increase its useful effect; The dynamo G comprises a field-magnet, The conductors consist in a limited number whereof only the pole-pieces N S are shown of thick bars of a good conducting material, in the drawings, and an armature F, carrying such as copper, the said number depending six coils B 3 C G D D, arranged at angles 30 upon the number. of alternatingcurrents eniof sixty degrees apart from each other, and So ployed. If, for instance, there is but one pair the opposite ones whereof are connected toof eireumrotating poles, and if two alternatgether, so that when the armature is rotated ing currents are employed whose phases are there will be generated in the three pairs of shifted in respect to each other by one-quarcoils three alternating currents differing in 35 ter of a phase, the number of conductor-bars their phases by one-sixth of a phase. The

is four, while if with the two poles three altercoils l3 and B are connected by conductingnating currents having their phases shifted wires to the respective bars I) b of the motor, by one-sixth of a phase are used, six bars are the coils G C to the bars 0 c, and the coilsD Wanted, &c. These bars are passed through D to the bars (Z (1', so that three circuits are 40 the body of iron composed of divisional parts, obtained. (The contact rings and brushes resuch as disks, and they are insulated therequied for this connection have been omittedin from. Besides,theyare all well conductively the drawings.) Under these conditions the connected together at one endfor instance, combined operation of the three currents will by a disk, a ring, or a star of metalwhile to have the effect of producing in the motor a t5 the other ends are attached thenvires that rotatingmagnetic fiel hwherebythe armature supply the currents. This system of connectf is put in rotation. The coils of the said aring together at one point the conductors apmature fare of the closed-circuit type2'. 6., pertaining to different circuits is possible, bethe terminals of each coil are connected tocanse in all the conductors there is from the gether and they are not supplied with current 50 source of current to the aforesaid point of from outside. The number of these coils is are connected to the other ends of the said bars, and means for exciting in the said circults dil'terential-phase alternating currents, sulj stantially as described.

In testiniony whereof I have hereunto set my hand in the presence of two subscribing Witnesses.

HIU IIAEL VON llOhlYO-llOlllt0lVO LSKY.

Witnesses:

OSKAV VON GOEBEN, SIMON Roos. 

